diff --git a/src/client/src/tscPrepare.c b/src/client/src/tscPrepare.c
index 7e62afefe6..ef8ddfd211 100644
--- a/src/client/src/tscPrepare.c
+++ b/src/client/src/tscPrepare.c
@@ -75,7 +75,6 @@ static int normalStmtAddPart(SNormalStmt* stmt, bool isParam, char* str, uint32_
   if (isParam) {
     ++stmt->numParams;
   }
-
   return TSDB_CODE_SUCCESS;
 }
 
diff --git a/src/client/src/tscProfile.c b/src/client/src/tscProfile.c
index 61bc9dd99e..15390ef201 100644
--- a/src/client/src/tscProfile.c
+++ b/src/client/src/tscProfile.c
@@ -197,8 +197,10 @@ void tscKillStream(STscObj *pObj, uint32_t killId) {
   }
 
   pthread_mutex_unlock(&pObj->mutex);
-
-  tscTrace("%p stream:%p is killed, streamId:%d", pStream->pSql, pStream, killId);
+  
+  if (pStream) {
+    tscTrace("%p stream:%p is killed, streamId:%d", pStream->pSql, pStream, killId);
+  }
 
   taos_close_stream(pStream);
   if (pStream->callback) {
diff --git a/src/client/src/tscSQLParser.c b/src/client/src/tscSQLParser.c
index 752c5d123f..ac2b958be7 100644
--- a/src/client/src/tscSQLParser.c
+++ b/src/client/src/tscSQLParser.c
@@ -248,7 +248,6 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
     }
 
     case USE_DATABASE: {
-      const char* msg = "db name too long";
       pCmd->command = TSDB_SQL_USE_DB;
 
       SSQLToken* pToken = &pInfo->pDCLInfo->a[0];
@@ -258,6 +257,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       }
 
       if (pToken->n > TSDB_DB_NAME_LEN) {
+        const char* msg = "db name too long"; 
         return invalidSqlErrMsg(pCmd, msg);
       }
 
@@ -295,8 +295,6 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
 
     case ALTER_DATABASE:
     case CREATE_DATABASE: {
-      const char* msg2 = "name too long";
-      const char* msg3 = "invalid db name";
 
       if (pInfo->sqlType == ALTER_DATABASE) {
         pCmd->command = TSDB_SQL_ALTER_DB;
@@ -307,11 +305,13 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
 
       SCreateDBInfo* pCreateDB = &(pInfo->pDCLInfo->dbOpt);
       if (tscValidateName(&pCreateDB->dbname) != TSDB_CODE_SUCCESS) {
+        const char* msg3 = "invalid db name";
         return invalidSqlErrMsg(pCmd, msg3);
       }
 
       int32_t ret = setObjFullName(pMeterMetaInfo->name, getAccountId(pSql), &(pCreateDB->dbname), NULL, NULL);
       if (ret != TSDB_CODE_SUCCESS) {
+        const char* msg2 = "name too long"; 
         return invalidSqlErrMsg(pCmd, msg2);
       }
 
@@ -347,13 +347,8 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       pCmd->command = (pInfo->sqlType == CREATE_USER) ? TSDB_SQL_CREATE_USER : TSDB_SQL_CREATE_ACCT;
       assert(pInfo->pDCLInfo->nTokens >= 2);
 
-      const char* msg = "name or password too long";
-      const char* msg1 = "password can not be empty";
-      const char* msg2 = "invalid user/account name";
-      const char* msg3 = "password needs single quote marks enclosed";
-      const char* msg4 = "invalid state option, available options[no, r, w, all]";
-
       if (pInfo->pDCLInfo->a[1].type != TK_STRING) {
+        const char* msg3 = "password needs single quote marks enclosed";
         return invalidSqlErrMsg(pCmd, msg3);
       }
 
@@ -362,15 +357,18 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       pInfo->pDCLInfo->a[1].n = strlen(pInfo->pDCLInfo->a[1].z);
 
       if (pInfo->pDCLInfo->a[1].n <= 0) {
+        const char* msg1 = "password can not be empty";
         return invalidSqlErrMsg(pCmd, msg1);
       }
 
       if (pInfo->pDCLInfo->a[0].n > TSDB_USER_LEN || pInfo->pDCLInfo->a[1].n > TSDB_PASSWORD_LEN) {
-        return invalidSqlErrMsg(pCmd, msg);
+        const char* msg = "name or password too long";
+        return invalidSqlErrMsg(pCmd, msg); 
       }
 
       if (tscValidateName(&pInfo->pDCLInfo->a[0]) != TSDB_CODE_SUCCESS) {
-        return invalidSqlErrMsg(pCmd, msg2);
+        const char* msg2 = "invalid user/account name";
+        return invalidSqlErrMsg(pCmd, msg2); 
       }
 
       strncpy(pMeterMetaInfo->name, pInfo->pDCLInfo->a[0].z, pInfo->pDCLInfo->a[0].n);  // name
@@ -403,7 +401,8 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
           } else if (strncmp(pAcctOpt->stat.z, "no", 2) == 0 && pAcctOpt->stat.n == 2) {
             pCmd->defaultVal[8] = 0;
           } else {
-            return invalidSqlErrMsg(pCmd, msg4);
+            const char* msg4 = "invalid state option, available options[no, r, w, all]";
+            return invalidSqlErrMsg(pCmd, msg4); 
           }
         }
       }
@@ -415,13 +414,10 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       assert(num >= 1 && num <= 2);
 
       const char* msg = "password too long";
-      const char* msg1 = "password can not be empty";
-      const char* msg2 = "invalid user/account name";
-      const char* msg3 = "password needs single quote marks enclosed";
-      const char* msg4 = "invalid state option, available options[no, r, w, all]";
 
       if (num == 2) {
         if (pInfo->pDCLInfo->a[1].type != TK_STRING) {
+          const char* msg3 = "password needs single quote marks enclosed";
           return invalidSqlErrMsg(pCmd, msg3);
         }
 
@@ -430,6 +426,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
         pInfo->pDCLInfo->a[1].n = strlen(pInfo->pDCLInfo->a[1].z);
 
         if (pInfo->pDCLInfo->a[1].n <= 0) {
+          const char* msg1 = "password can not be empty";
           return invalidSqlErrMsg(pCmd, msg1);
         }
 
@@ -445,6 +442,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
       }
 
       if (tscValidateName(&pInfo->pDCLInfo->a[0]) != TSDB_CODE_SUCCESS) {
+        const char* msg2 = "invalid user/account name";
         return invalidSqlErrMsg(pCmd, msg2);
       }
 
@@ -475,6 +473,7 @@ int32_t tscToSQLCmd(SSqlObj* pSql, struct SSqlInfo* pInfo) {
         } else if (strncmp(pAcctOpt->stat.z, "no", 2) == 0 && pAcctOpt->stat.n == 2) {
           pCmd->defaultVal[8] = 0;
         } else {
+          const char* msg4 = "invalid state option, available options[no, r, w, all]";
           return invalidSqlErrMsg(pCmd, msg4);
         }
       }
@@ -1868,8 +1867,6 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, int32_t colIdx, tSQLExprItem* pItem
   SMeterMetaInfo* pMeterMetaInfo = NULL;
   int32_t         optr = pItem->pNode->nSQLOptr;
 
-  int32_t numOfAddedColumn = 1;
-
   const char* msg1 = "not support column types";
   const char* msg2 = "invalid parameters";
   const char* msg3 = "illegal column name";
@@ -2166,6 +2163,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, int32_t colIdx, tSQLExprItem* pItem
       int16_t resultSize = pSchema[index.columnIndex].bytes;
 
       char val[8] = {0};
+      int32_t numOfAddedColumn = 1; 
       if (optr == TK_PERCENTILE || optr == TK_APERCENTILE) {
         tVariantDump(pVariant, val, TSDB_DATA_TYPE_DOUBLE);
 
@@ -2190,6 +2188,7 @@ int32_t addExprAndResultField(SSqlCmd* pCmd, int32_t colIdx, tSQLExprItem* pItem
         SSqlExpr* pExpr = tscSqlExprInsert(pCmd, colIdx, functionId, &index, resultType, resultSize, resultSize);
         addExprParams(pExpr, val, TSDB_DATA_TYPE_DOUBLE, sizeof(double), 0);
       } else {
+
         tVariantDump(pVariant, val, TSDB_DATA_TYPE_BIGINT);
 
         int64_t nTop = *((int32_t*)val);
diff --git a/src/client/src/tscSecondaryMerge.c b/src/client/src/tscSecondaryMerge.c
index 5eebddca73..737c1342d8 100644
--- a/src/client/src/tscSecondaryMerge.c
+++ b/src/client/src/tscSecondaryMerge.c
@@ -1314,8 +1314,10 @@ int32_t tscLocalDoReduce(SSqlObj *pSql) {
     tscTrace("%s call the drop local reducer", __FUNCTION__);
 
     tscDestroyLocalReducer(pSql);
-    pRes->numOfRows = 0;
-    pRes->row = 0;
+    if (pRes) {
+      pRes->numOfRows = 0;
+      pRes->row = 0;
+    }
     return 0;
   }
 
diff --git a/src/client/src/tscServer.c b/src/client/src/tscServer.c
index 1805eac38d..ed21a82be1 100644
--- a/src/client/src/tscServer.c
+++ b/src/client/src/tscServer.c
@@ -2312,6 +2312,7 @@ int tscBuildCreateTableMsg(SSqlObj *pSql) {
   size = tscEstimateCreateTableMsgLength(pSql);
   if (TSDB_CODE_SUCCESS != tscAllocPayload(pCmd, size)) {
     tscError("%p failed to malloc for create table msg", pSql);
+    free(tmpData); 
     return -1;
   }
 
diff --git a/src/client/src/tscSystem.c b/src/client/src/tscSystem.c
index 60b90ac328..2ebd1cfc51 100644
--- a/src/client/src/tscSystem.c
+++ b/src/client/src/tscSystem.c
@@ -230,7 +230,7 @@ static int taos_options_imp(TSDB_OPTION option, const char *pStr) {
         return -1;
       }
 
-      if (cfg && cfg && cfg->cfgStatus <= TSDB_CFG_CSTATUS_OPTION) {
+      if (cfg && cfg->cfgStatus <= TSDB_CFG_CSTATUS_OPTION) {
         char sep = '.';
 
         if (strlen(tsLocale) == 0) { // locale does not set yet
diff --git a/src/kit/shell/src/shellEngine.c b/src/kit/shell/src/shellEngine.c
index c66f6f4be7..ed3b71bfcd 100644
--- a/src/kit/shell/src/shellEngine.c
+++ b/src/kit/shell/src/shellEngine.c
@@ -780,6 +780,7 @@ void source_file(TAOS *con, char *fptr) {
 
   if (wordexp(fptr, &full_path, 0) != 0) {
     fprintf(stderr, "ERROR: illegal file name\n");
+    free(cmd);
     return;
   }
 
@@ -788,6 +789,7 @@ void source_file(TAOS *con, char *fptr) {
   if (access(fname, R_OK) == -1) {
     fprintf(stderr, "ERROR: file %s is not readable\n", fptr);
     wordfree(&full_path);
+    free(cmd);
     return;
   }
 
@@ -795,6 +797,7 @@ void source_file(TAOS *con, char *fptr) {
   if (f == NULL) {
     fprintf(stderr, "ERROR: failed to open file %s\n", fname);
     wordfree(&full_path);
+    free(cmd);
     return;
   }
 
diff --git a/src/kit/shell/src/shellLinux.c b/src/kit/shell/src/shellLinux.c
index ad8bf6c5c3..2e2c44af1a 100644
--- a/src/kit/shell/src/shellLinux.c
+++ b/src/kit/shell/src/shellLinux.c
@@ -277,7 +277,10 @@ void *shellLoopQuery(void *arg) {
   pthread_cleanup_push(cleanup_handler, NULL);
 
   char *command = malloc(MAX_COMMAND_SIZE);
-
+  if (command == NULL){
+    tscError("failed to malloc command");
+    return NULL;
+  }
   while (1) {
     // Read command from shell.
 
@@ -286,10 +289,8 @@ void *shellLoopQuery(void *arg) {
     shellReadCommand(con, command);
     reset_terminal_mode();
 
-    if (command != NULL) {
-      // Run the command
-      shellRunCommand(con, command);
-    }
+    // Run the command
+    shellRunCommand(con, command);
   }
 
   pthread_cleanup_pop(1);
diff --git a/src/modules/http/src/gcJson.c b/src/modules/http/src/gcJson.c
index 0cb20ec7e1..ecd9235644 100644
--- a/src/modules/http/src/gcJson.c
+++ b/src/modules/http/src/gcJson.c
@@ -119,7 +119,7 @@ bool gcBuildQueryJson(HttpContext *pContext, HttpSqlCmd *cmd, TAOS_RES *result,
     cmd->numOfRows += numOfRows;
   }
 
-  for (int i = 0; i < numOfRows; ++i) {
+  for (int k = 0; k < numOfRows; ++k) {
     TAOS_ROW row = taos_fetch_row(result);
 
     // for group by
diff --git a/src/modules/http/src/restJson.c b/src/modules/http/src/restJson.c
index 8aa0ac5069..6c04d39f45 100644
--- a/src/modules/http/src/restJson.c
+++ b/src/modules/http/src/restJson.c
@@ -94,7 +94,7 @@ bool restBuildSqlJson(HttpContext *pContext, HttpSqlCmd *cmd, TAOS_RES *result,
   int         num_fields = taos_num_fields(result);
   TAOS_FIELD *fields = taos_fetch_fields(result);
 
-  for (int i = 0; i < numOfRows; ++i) {
+  for (int k = 0; k < numOfRows; ++k) {
     TAOS_ROW row = taos_fetch_row(result);
 
     // data row array begin
diff --git a/src/modules/http/src/tgHandle.c b/src/modules/http/src/tgHandle.c
index ac17d6da09..80a178c776 100644
--- a/src/modules/http/src/tgHandle.c
+++ b/src/modules/http/src/tgHandle.c
@@ -262,6 +262,8 @@ int tgReadSchema(const char *fileName) {
   size_t result = fread(content, 1, contentSize, fp);
   if (result != contentSize) {
     httpError("failed to read telegraf schema file:%s", fileName);
+    fclose(fp);
+    free(content);
     return -1;
   }
 
diff --git a/src/os/linux/src/tsystem.c b/src/os/linux/src/tsystem.c
index 03192bb9cc..0a9d97b3cf 100644
--- a/src/os/linux/src/tsystem.c
+++ b/src/os/linux/src/tsystem.c
@@ -124,7 +124,7 @@ bool taosGetSysCpuInfo(SysCpuInfo *cpuInfo) {
   }
 
   char cpu[10] = {0};
-  sscanf(line, "%s %ld %ld %ld %ld", cpu, &cpuInfo->user, &cpuInfo->nice, &cpuInfo->system, &cpuInfo->idle);
+  sscanf(line, "%s %lu %lu %lu %lu", cpu, &cpuInfo->user, &cpuInfo->nice, &cpuInfo->system, &cpuInfo->idle);
 
   tfree(line);
   fclose(fp);
@@ -150,7 +150,7 @@ bool taosGetProcCpuInfo(ProcCpuInfo *cpuInfo) {
   for (int i = 0, blank = 0; line[i] != 0; ++i) {
     if (line[i] == ' ') blank++;
     if (blank == PROCESS_ITEM) {
-      sscanf(line + i + 1, "%ld %ld %ld %ld", &cpuInfo->utime, &cpuInfo->stime, &cpuInfo->cutime, &cpuInfo->cstime);
+      sscanf(line + i + 1, "%lu %lu %lu %lu", &cpuInfo->utime, &cpuInfo->stime, &cpuInfo->cutime, &cpuInfo->cstime);
       break;
     }
   }
diff --git a/src/system/detail/src/mgmtVgroup.c b/src/system/detail/src/mgmtVgroup.c
index e3bed57b33..2bc1801a68 100644
--- a/src/system/detail/src/mgmtVgroup.c
+++ b/src/system/detail/src/mgmtVgroup.c
@@ -289,6 +289,7 @@ int mgmtRetrieveVgroups(SShowObj *pShow, char *data, int rows, SConnObj *pConn)
 
   SDbObj *pDb = NULL;
   if (pConn->pDb != NULL) pDb = mgmtGetDb(pConn->pDb->name);
+  assert(pDb != NULL);
 
   pVgroup = pDb->pHead;
   while (pVgroup != NULL) {
diff --git a/src/system/detail/src/vnodeQueryImpl.c b/src/system/detail/src/vnodeQueryImpl.c
index 5174753d82..d5809d1b72 100644
--- a/src/system/detail/src/vnodeQueryImpl.c
+++ b/src/system/detail/src/vnodeQueryImpl.c
@@ -4555,8 +4555,7 @@ static void doMerge(SQueryRuntimeEnv *pRuntimeEnv, int64_t timestamp, tFilePage
 }
 
 static void printBinaryData(int32_t functionId, char *data, int32_t srcDataType) {
-  if (functionId == TSDB_FUNC_FIRST_DST || functionId == TSDB_FUNC_LAST_DST || functionId == TSDB_FUNC_FIRST_DST ||
-      functionId == TSDB_FUNC_LAST_DST) {
+  if (functionId == TSDB_FUNC_FIRST_DST || functionId == TSDB_FUNC_LAST_DST) {
     switch (srcDataType) {
       case TSDB_DATA_TYPE_BINARY:
         printf("%ld,%s\t", *(TSKEY *)data, (data + TSDB_KEYSIZE + 1));